It is well known to manufacture thin plastic articles such as disposable drink cup lids by vacuum thermoforming. Such articles are manufactured by causing a web of extruded plastic sheet material to contact a metal die having the desired shape of the article formed into a surface thereof. Vacuum is applied to the platen surface through small holes to draw the plastic material over the contours of the die. The articles are thereafter cooled, separated from the web by die cutting, and stacked and/or boxed using conventional automation devices.
It is also known to vacuum form logos and other indicia on the plastic lids. Such indicia are typically formed of raised surfaces in a central deck area of the lid. Because thermoformed plastic lids are usually of one color, it is difficult to clearly see such vacuum embossed indicia. To add definition, the raised surfaces of the embossed indicia may be colored in a secondary operation carried out by printing machinery separate from the thermoforming machinery.